Preliminary Product Information

This document contains information for a new product.
Cirrus Logic reserves the right to modify this product without notice.

Cirrus Logic, Inc. 2000

P.O. Box 17847, Austin, Texas 78760
(512) 445 7222 FAX: (512) 445 7581
http://www.cirrus.com

CrystalClearTM AC '97 2 Channel Low Cost PCI Audio Reference Design

Features

2 Channel Low Cost High Performance PCI
Audio Accelerator add-in card

CS4281 PCI Audio Controller and CS4297A
Audio Codec `97

Complete suite of Analog I/O connections:

Line, Mic, CD, and Aux Inputs
Line and Headphone Outputs

S/PDIF (IEC-958) digital output

ZV Port Input

Joystick/MIDI Interface

2-layer low cost adapter board

Exceeds Microsoft's

PC 99 audio

performance specifications.

Complies with the AC `97 version 2.1
specification

Description

The CRD4281-15 is a low cost PCI add-in board refer-
ence design that showcases Cirrus Logic's
CS4281 audio controller and the CS4297A audio co-
dec. The card features two channel 20-bit DACs, two
channel 18-bit ADCs, an optional ZV port digital input,
and a S/PDIF digital output.

The CRD4281-15 reference design is available by or-
dering the CMK4281-15 manufacturing kit. Use this kit
to help you develop high quality PCI add-in cards and
PC motherboard audio designs. The CMK4281-15 in-
cludes a full set of schematic design files (OrCAD

7.2

format), PCB job files (PADS

ASCII), PCB artwork

files, and bill of materials. This design is production
ready. It can also be easily modified to meet your spe-
cific requirements.

ORDERING INFO
CMK4281-15 (Manufacturing Kit)

PC BEEP

AUX IN

INT MODEM

ZV PORT

CD IN

CDR4281-15

CS4297A

LINE IN

LINE OUT

MIC IN

HP OUT

MIDI /
JOYSTICK

SPDIF OUT

JUN `00

DS308RD15A1

CRD4281-15

CRD4281-15

DS308RD15A1

TABLE OF CONTENTS

1. GENERAL INFORMATION ...................................................................................4
2. SCHEMATIC DESCRIPTION ................................................................................4

2.1 Analog Inputs ..............................................................................................4
2.2 ZV Port Digital Input ....................................................................................5
2.3 Line Output .................................................................................................5
2.4 Headphone Output and Anti-Pop Circuitry .................................................5
2.5 CS4281 PCI Controller ...............................................................................5
2.6 CS4297A Audio Codec ..............................................................................5
2.7 Mic Pre-amp and Phantom Power ..............................................................5
2.8 MIDI and Joystick Connection ....................................................................5
2.9 S/PDIF Output ............................................................................................6
2.10 PCI Bus Connection .................................................................................6
2.11 Component Selection ...............................................................................6
2.12 EMI Components ......................................................................................6

3. GROUNDING AND LAYOUT ................................................................................7

3.1 Partitioned Voltage and Ground Planes .....................................................7
3.2 CS4297A Layout Notes ..............................................................................7

4. REFERENCES .......................................................................................................8

4.1 ADDENDUM ...............................................................................................8

5. BILL OF MATERIALS .........................................................................................27

Contacting Cirrus Logic Support

For a complete listing of Direct Sales, Distributor, and Sales Representative contacts, visit the Cirrus Logic web site at:
http://www.cirrus.com/corporate/contacts/

Microsoft , Windows 95, Windows 98 and Windows Millennium and WHQL is registered trademark of Microsoft.
CrystalClear is a trademark of Cirrus Logic, Inc.
Intel is a registered trademark of Intel Corporation.
OrCAD is a registered trademark of OrCAD, Inc.
PADS is a registered trademark of, PADS Software, Inc.

Preliminary product information describes products which are in production, but for which full characterization data is not yet available. Advance product information
describes products which are in development and subject to development changes. Cirrus Logic, Inc. has made best efforts to ensure that the information contained
in this document is accurate and reliable. However, the information is subject to change without notice and is provided "AS IS" without warranty of any kind (express
or implied). No responsibility is assumed by Cirrus Logic, Inc. for the use of this information, nor for infringements of patents or other rights of third parties. This
document is the property of Cirrus Logic, Inc. and implies no license under patents, copyrights, trademarks, or trade secrets. No part of this publication may be
copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) without the prior
written consent of Cirrus Logic, Inc. Items from any Cirrus Logic website or disk may be printed for use by the user. However, no part of the printout or electronic
files may be copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) with-
out the prior written consent of Cirrus Logic, Inc.Furthermore, no part of this publication may be used as a basis for manufacture or sale of any items without the
prior written consent of Cirrus Logic, Inc. The names of products of Cirrus Logic, Inc. or other vendors and suppliers appearing in this document may be trademarks
or service marks of their respective owners which may be registered in some jurisdictions. A list of Cirrus Logic, Inc. trademarks and service marks can be found
at http://www.cirrus.com.

CRD4281-15

DS308RD15A1

LIST OF FIGURES

Figure 1. Block Diagram .................................................................................................... 9
Figure 2. Audio In ............................................................................................................ 10
Figure 3. ZV Port Digital Input and PC Beep Input .......................................................... 11
Figure 4. Line Out ............................................................................................................ 12
Figure 5. Headphone Output and Output Mute Circuit .................................................... 13
Figure 6. CS4281 PCI Audio Controller ........................................................................... 14
Figure 7. CS4297A Codec ............................................................................................... 15
Figure 8. Microphone Input Circuit .................................................................................. 16
Figure 9. MIDI and Joystick Control ................................................................................ 17
Figure 10. S/PDIF Consumer Digital Output ................................................................... 18
Figure 11. PCI Bus .......................................................................................................... 19
Figure 12. Power ............................................................................................................. 20
Figure 13. Top Assembly Drawing .................................................................................. 21
Figure 14. Top Silkscreen ................................................................................................ 22
Figure 15. PCB Layout: Top Layer .................................................................................. 23
Figure 16. PCB Layout: Bottom Layer ............................................................................. 24
Figure 17. Drill Drawing and Manufacturing Instructions ................................................. 25
Figure 18. Bracket Drawing ............................................................................................. 26

CRD4281-15

DS308RD15A1

1. GENERAL INFORMATION

The CRD4281-15 is a PCI add-in card that features
the CS4281 PCI audio controller and the CS4297A
AC-97 audio codec. The CRD4281-15 is a low cost
board with a rich feature set and industry leading
audio performance. In order to maintain high audio
quality, careful consideration has been given to
component selection and PC layout.

The CS4297A is a mixed-signal serial audio codec
based on the Intel AC `97 2.1 specification. The
CS4297A features a 20-bit stereo DAC, an 18-bit
stereo ADC, a digital S/PDIF output, and a very
flexible analog audio mixer. The CS4297A has
four line-level stereo inputs, two mono line-level
inputs, two switchable microphone inputs, and a
stereo pseudo-differential CD input. The input sig-
nals can be routed to the ADC for recording, or
mixed together for recording and direct playback.
The CS4297A has 64 registers that are used to con-
trol its various features such as volume levels,
mutes and signal routing. The CS4297A maintains
high audio quality throughout its signal chain and
exceeds the Microsoft PC-99 audio performance
specification.

The CS4281 controller streams digital audio data
and MIDI over the PCI bus. It also performs hard-
ware-controlled signal processing and sample rate
conversion. The CS4281 features several peripher-
al interfaces including MIDI output, joystick and
game controller input, hardware volume control
and several General Purpose I/Os.

The CS4297A and the CS4281 communicate
through a 5-wire serial digital interface known as
the AC-Link. The AC-Link is used to transfer dig-
ital audio between the two devices. Its is also used
to send commands from the CS4281 to the
CS4297A's registers. For more information on the
AC-Link, see the AC'97 version 2.1 specification.

2. SCHEMATIC DESCRIPTION

The block diagram in Figure 1 illustrates the inter-
connections between the schematic pages. The fol-
lowing are descriptions of the other pages
contained in the schematics.

2.1

Analog Inputs

The inputs for AUX, CD, and LINE shown in
Figure 2 are attenuated 6dB by a voltage dividers.
This allows for input levels up to 2 Vrms. Each of
these inputs has 220 pF EMI suppression capaci-
tors. These may be removed if EMC testing deter-
mines they are not required.

The CS4297A analog inputs and outputs need to
be AC coupled because of internal bias voltages.
10 uF AC coupling capacitors are used on the Line,
CD, Aux, and Internal Modem inputs to minimize
low frequency roll-off. The CS4297A CD input is
pseudo-differential. The CD signal acts as one side
of the differential input and CD_COM as the other.
CD_COM is a common return path for both the left
and right channels. For good common mode rejec-
tion performance, the voltage divider resistors for
CD_COM have been set to half the value of those
for CD L and R inputs.

There are provisions for two types of analog audio
CD connectors. J1 is for the standard ATAPI con-
nector and J2 is for the legacy 2 mm Mitsumi con-
nector. You can install only one of the two
connectors because the footprints of J1 and J2 are
placed on top of each other.

The CRD4281-15 has circuitry to accommodate
the audio from a modem. The modem connection
uses the CS4297A's MONO_OUT and
PHONE_IN. The MONO_OUT circuit has a volt-
age divider that can be adjusted to accommodate
small output levels.

CRD4281-15

DS308RD15A1

2.2

ZV Port Digital Input

The ZV port in Figure 3, accepts PCM audio data
in I

S serial format and routes it to the CS4334

DAC. The analog output of this DAC is connected
to the VIDEO_IN audio inputs of the CS4297A.

2.3

Line Output

The LINE_OUT circuit in Figure 4 consists of a
Motorola MC1458 dual op-amp. This device is ca-
pable of driving high impedance line level signals,
such as powered speakers, and stereo headphones
with impedances greater than 32

. This circuit has

a gain of 6 dB. The output of the op-amp is con-
nected to an anti-pop circuit that is described in
Figure 5. This anti-pop circuit suppresses power-
on transient pops.

2.4

Headphone Output and Anti-Pop
Circuitry

The headphone output circuit in Figure 5 consists
of a Motorola MC1458 dual op-amp connected to
the ALT_LINE_OUT of the CS4297A. The
MC1458 circuit has a gain of 6 dB and is capable
of driving stereo headphones with impedances
greater than 32

The headphone output is connected to an anti-pop
circuit. During power up, transistors Q5-Q8 in the
anti-pop circuit suppress power-on transients by
temporarily muting the audio output.

2.5

CS4281 PCI Controller

The CS4281, in Figure 6, has 0.1

F decoupling

capacitors connected to each of its power pins. All
of these capacitors are located physically close to
the device. L3, C56, and C57 are used to filter the
power supply for the internal PLL circuit.

The AC-Link requires series termination resistors
to prevent reflections. The resistors are placed as
close as possible to device originating the signal.
The CS4281 generates SYNC and SDATA_OUT
and each has a 47 ohm series termination resistor,
R19 and R20.

All unused inputs and bi-directional pins on the
CS4281 are tied to their respective inactive levels
through a 10 k

resistor.

2.6

CS4297A Audio Codec

The audio codec is shown in Figure 7. All analog
inputs are sent to the codec from the circuitry in
Figure 2 (Audio In) and Figure 8 (Microphone In).
All of these signals are AC coupled. Unused analog
input should be tied to Vref (pin 28) or AC coupled
to ground through a capacitor to prevent noise. Mic
2 is the only unused input on the CRD4281-15 and
is tied directly to Vref.

The CS4297A generates two AC-Link signals,
BITCLK and SDATA_IN. Both outputs have a
47

series termination resistor to prevent reflec-

tions on the AC-Link.

2.7

Mic Pre-amp and Phantom Power

The microphone pre-amp in figure 8 uses a Motor-
ola MC33078D low noise dual op-amp. One of the
op-amps provides 18 dB gain stage for the micro-
phone. The other op-amp buffers the phantom pow-
er supply for the mic. The phantom power is
derived from the +5 V analog supply and buffered
by U10A to provide a maximum of +4.2 V with no
load and a minimum of +2.0 V under a 0.8 mA
load, as required by PC 99. The microphone circuit
also has 3 dB rolloffs at 60 Hz and 15 kHz as spec-
ified in PC-99.

2.8

MIDI and Joystick Connection

The MIDIOUT buffer driver circuit in Figure 9 is
used to provide +5 V TTL compatible output on the
DB-15 connector. This circuit can be removed, and
R37 populated to bypass the buffer circuit if a
+3.3 V compatible output is sufficient. L4, C72,
C77, C78, C79 are provided for EMI suppression
and can be removed if EMC testing shows they are
not required. In this case, replace L4 with a 0

re-

sistor. C73 - C76 and C80 - C83 are required for the

CRD4281-15

DS308RD15A1

joystick circuitry to be functional and must not be
removed.

2.9

S/PDIF Output

The S/PDIF (IEC-958) digital output, in Figure 10,
is compatible with digital inputs on consumer de-
vices such as consumer stereo receivers and
MiniDisk recorders. The CS4297A S/PDIF output
is coupled to J16 through an isolation transformer.
This design uses a low cost industry standard de-
vice, the PE65612 by Pulse Engineering.

The S/PDIF and DAC outputs are derived from the
same 48 KHz PCM signal. This means that what-
ever digitally effects LINE_OUT, such as sample
rate conversion, also effects the S/PDIF output.

2.10

PCI Bus Connection

The PCI 2.1 specification requires that each unused
+3.3 V power pin should be connected with an av-
erage of 0.01

F capacitor. In Figure 11, seven

0.1

F capacitors in parallel provide the required

capacitance for the +3.3 V power pins.

Power Supplies

The CS4297A requires both a digital +3.3 V and an
analog +5 V supply. The digital power is supplied
from the PCI bus. A separate regulator is recom-
mended for the analog voltage supply to provide
good audio signal quality. In Figure 12, a Motorola
MC78M05 regulates the +12 V supply from the
PCI bus down to a clean +5 V analog supply. For
the best audio performance, the analog voltage reg-
ulator, should be located near the CS4297A. Op-
tionally, U3, a 78L05, can be used in applications
where LINE_OUT and ALT_LINE_OUT are only
going to drive high impedance loads (10 K

greater). The -12 V power pin is decoupled through

C29 and C30, and supplies power to the headphone
circuit.

The Micrel MIC2920A low dropout regulator is
provides the required +3.3 V to the CS4281 in the
absence of +3.3 V on the PCI bus. Two packaging
options are supported. U8 is a SOT-223 surface
mount package, and U9 is a TO-220 through hole
package. 0

resistors are provided as a build op-

tion if +3.3 V is guaranteed to be available on the
PCI bus.

2.11

Component Selection

Great attention was given to the particular compo-
nents used on the CRD4281-15 board with cost,
performance, and package selection as the most im-
portant factors. Listed are some of the guidelines
used in the selection of components:

No components smaller than 0805 package.

Only single package components; no resistor
packs.

8-pin devices are in surface mount packages.

Dual footprint for the 24.576 MHz. crystal.
Standard H49S, and small circular CA-301
through hole package.

Dual footprint for +5 V and +3.3 V regulators.
Surface mount and through hole packages are
supported.

2.12

EMI Components

A number of capacitors and inductors are included
to help the board meet EMI compliance tests, such
as FCC Part 15. Modifying this selection of compo-
nents without EMC testing could result in EMC
compliance failure.

CRD4281-15

DS308RD15A1

3. GROUNDING AND LAYOUT

The component layout and signal routing of the
CRD4281-15 provides a good model for laying out
your own PCI add-in card. PCI-bus based add-in
cards have explicit requirements on trace lengths
that are not imposed on motherboard designs.
These trace length limits for add-in cards are as fol-
lows:

Maximum trace length for 32-bit signals on 32-
bit and 64-bit cards is 1.5 inches.

Maximum trace lengths for signals on the 64-
bit extension are 2 inches.

Trace length for the PCI CLK signal is 2.5
inches ± 0.1 inch.

The PCI CLK signal must drive only one load.

Please refer to the PCI 2.1 Specification , Section
4.3.6, for information on routing PCI bus signals on
a motherboard.

3.1

Partitioned Voltage and Ground
Planes

The CRD4281-15 is partitioned into separate digi-
tal and analog sections to prevent digital noise from
affecting the performance of the analog circuits.
The analog section is completely isolated from the
digital section. The analog and digital sections each
have their own separate ground plane. All analog
components, power traces and signal traces lie over
the analog ground plane. Digital components, pow-
er traces and signal traces are not allowed to cross-
over into the analog section.

The CS4297A is placed at the transition point be-
tween the analog and digital ground planes. The

pins are arranged on the CS4297A so that the ana-
log and digital signals are separated from each oth-
er. The analog and digital ground planes must be
tied together for the codec to maintain proper volt-
age references. For best results, the two ground
planes are tied together with a single wide trace un-
der the codec near its digital ground pins.

Data converters are generally susceptible to noise
on the crystal pins. In order reduce noise from cou-
pling onto these pins, the area around the crystal
and its signal traces is filled with copper on the top
and bottom of the PCB and attached to digital
ground.

A separate chassis ground provides a reference
plane for all of the EMI suppression components.
The chassis ground plane is connected to the analog
ground plane at the external jacks.

3.2

CS4297A Layout Notes

Refer to the CS4297A Data Sheet for partitioning
and bypass capacitors placement. Pay close atten-
tion to bypass capacitors on REFFLT, AFLT1,
AFLT2 and the power supply capacitors.

CRD4281-15

DS308RD15A1

4. REFERENCES

1) Intel, Audio Codec `97 Component Specification, Revision 2.1, May 22, 1998.

http://developer.intel.com/pc-supp/platform/ac97/

2) PCI Special Interest Group, PCI Local Bus Specification, Revision 2.1, June 1, 1995.

http://www.pcisig.com/

3) Cirrus Logic, CS4281 PCI Audio Interface Data Sheet

http://www.cirrus.com/products/overviews/cs4281.html

4) Cirrus Logic, CS4297A SoundFusion Audio Codec `97 Data Sheet

http://www.cirrus.com/products/overviews/CS4297A.html

5) Steve Harris, Clif Sanchez, Personal Computer Audio Quality Measurements, Ver 1.0

http://www.cirrus.com/products/papers/meas/meas.html

6) Microsoft, PC Design Guidelines,

http://www.microsoft.com/hwdev/desguid/

7) M. Montrose. Printed Circuit Board Design Techniques for EMC Compliance, IEEE Press, New York:

1996.

4.1

ADDENDUM

Schematic drawings

Layout drawings

Bracket drawings

Bill of materials

CRD4281-15

DS308RD15A1

PCI_BUS

PAR

STOP#

TRDY#

FRAME#

INTA#

RST#

GNT#

IDSEL

CLK

REQ#

IRDY#

AD[31..0]

PERR#

DEVSEL#

C/BE[3..0]#

CS4281

INTA#

REQ#

RST#

CLK

GNT#

IRDY#

TRDY#

STOP#

ASDOUT

ASDIN

ARST#

MIDIIN

MIDIOUT

JBCX

JBCY

JACY

AD[31..0]

JACX

JAB1

JAB2

JBB1

JBB2

ABITCLK

ASYNC

FRAME#

DEVSEL#

PERR#

PAR

IDSEL

C/BE[3..0]#

AUDIO IN

AUX_R

AUX_L

ZV_R
ZV_L

LINE_INL

LINE_INR

CD_INR
CD_INL
CD_COM

MONO_OUT

PHONE_IN

PCBEEP

CS4297A

CD_INR

CD_COM

LINE_INR

LINE_INL

MIC1

CD_INL

AUX_R
AUX_L

ASYNC

LINE_OUTR

ASDOUT

ASDIN

ABITCLK

ZV_L

ZV_R

PHONE_IN

ARST#

MONO_OUT

LINE_OUTL

ALT_LINE_OUTL
ALT_LINE_OUTR

PCBEEP

SPDIF_TX

Power

MIC IN

MIC1

Off Board Digital

JAB2

MIDIOUT

MIDIIN

JBB1
JBCY

JBB2

JACX

JBCX

JAB1
JACY

SPDIF_TX

AUDIO OUT

LINE_OUTL
LINE_OUTR

ALT_LINE_OUTR

ALT_LINE_OUTL

C/BE[3..0]#

AD[31..0]

Figure 1. Block Diagram

RD4281-15

308

RD15A

AGND

CGND

AGND

C12
10uF
ELEC

R45

6.8K

C7
10uF
ELEC

R46

6.8K

R48

6.8K

R57

3.4K

C14
220pF
NPO

C11
10uF
ELEC

C101
220pF
NPO

220pF
NPO

R49

6.8K

220pF
NPO

C2
10uF
ELEC

C10
220pF
NPO

R51

6.8K

C8
10uF
ELEC

220pF
NPO

R55

3.4K

C3
10uF
ELEC

C99
10uF
ELEC

R36

47K

4
3
5
2
1

R54

6.8K

R52

6.8K

C1
10uF
ELEC

C100
10uF
ELEC

B4B-PH-K

1
2
3
4

R34

27K

R61

6.8K

Out

G
G
In

J11

4X1HDR-SN/PB

R
G
G
L

4X1HDR-SN/PB

R35

47K

R62

6.8K

R50

6.8K

R47

6.8K

R
G
G
L

4X1HDR-SN/PB

R53

6.8K

C102
220pF
NPO

C9
220pF
NPO

C13
220pF
NPO

PHONE_IN

LINE_INL

CD_COM

AUX_R

MONO_OUT

CD_INR

LINE_INR

AUX_L

CD_INL

INTERNAL MODEM

TO MODEM

Connect CGND to

AGND at the

jack

GND

DO NOT

POPULATE

Line In

AUX IN

GND

CDROM IN

FROM MODEM

MITSUMI

Figure 2. Audio In

RD4281-15

308

RD15A

DGND

+3.3VD

DGND

+3.3VD

+5V_PCI

DGND

+3.3VD

DGND

+3.3VD

DGND

+3.3VD

AD26

AD25

AD16

AD15

AD28

AD2

AD17

AD20

AD11

AD14

AD21

AD30

AD4

AD0

AD5

AD19

AD24

AD12

AD18

AD22
AD23

AD[31..0]

AD8

AD13

AD3

AD7

AD9

AD31

AD29

AD27

AD1

AD6

AD10

C/BE2

C/BE0
C/BE1

C/BE3

C/BE[3..0]#

VOLDN

VOLUP

VOLDN

VOLUP

C57
0.1uF
X7R

C56
1000pF
NPO

120@100MHz

R65

100

R64

100

R20

R19

C104
100pF

COG

C105
100pF

COG

R63

10K

C58
0.1uF
X7R

24LC00

6
5

1
2

SCL
SDA

Vcc

nc1
nc2 nc4

Vss

nc3

C61
0.1uF
X7R

R21

4.7K

C67
0.1uF
X7R

C70
0.1uF
X7R

C65
0.1uF
X7R

C116
0.1uF
X7R

C59
0.1uF
X7R

C60
0.1uF
X7R

C66
0.1uF
X7R

C62
0.1uF
X7R

C64
0.1uF
X7R

C69
0.1uF
X7R

C117
0.1uF
X7R

C118
0.1uF
X7R

R76

4.7K

R77

4.7K

G
D

J12

4X1HDR-SN/PB

MQFP

CS4281

11
10

52
54
55
53

15
16
17
20
23
24

60
63
66

70
71
79
80
51

81
82
83
84
85

97
96

92
91
90
89
88

12
61

100

21
31
39
50

1
7
22
30
40
49

13
62
65

ABITCLK

AD23

ASDIN

AD22

AD21

AD20

AD19

ASDOUT

ASYNC

AD18

AD16
AD17

ARST

JAB1

JBB1

JACX
JBCX
JBCY
JACY

CBE2

FRAME
IRDY
TRDY
DEVSEL
STOP
PERR

IRQA

PAR

CBE1

AD15

AD14

AD13

AD12

AD11

AD10

AD09

AD08

CBEO

AD07

AD06

AD05

AD04

AD03

AD02

AD01

AD00

JBB2

JAB2

MIDIIN
MIDIOUT
ASDIN2/GPIO1

VOLUP
VOLDN
EECLK/GPOUT/PCREQ#
EEDAT/GPIO2/PCGNT#
TEST

INTA
RST
PCICLK
PCI_GNT
PCI_REQ

AD24
AD25

AD27
AD28
AD29
AD30
AD31

AD26

CRYVDD

IRQB

CVDD1
CVDD2

TESTSEL

3.3VAUX

PCIVDD0

GPIO3

PCIVDD2
PCIVDD3
PCIVDD4
PCIVDD5
PCIVDD6
PCIVDD7

CRYGND

PCIGND0

CLKRUN#

PCIGND2
PCIGND3
PCIGND4
PCIGND5
PCIGND6
PCIGND7

IRQC

CGND1
CGND2
CGND3

PME#

CBE3

IDSEL

VDD5REF

INTA#

REQ#

RST#
CLK
GNT#

IRDY#
TRDY#

STOP#

ASDIN

MIDIIN

MIDIOUT

JBCX
JBCY
JACY

AD[31..0]

JACX

JAB1
JAB2
JBB1
JBB2

FRAME#

DEVSEL#

PERR#
PAR

IDSEL

C/BE[3..0]#

ABITCLK

ARST#

ASYNC

ASDOUT

PIN 39

CS4281 PCIVDD PINS

PIN 50

PIN 31

PIN 86

PIN 8

PIN 21

CS4281 CVDD PINS

PIN 12

PIN 68

CS4281 3.3VAUX PIN

Hardware Volume
Control

PIN 8

PIN 21

PIN 31

PIN 39

PIN 61

PIN 67

Do not populate R76 &
R77 for Cs4281

PIN 100

Backwards compatible

connections for CS4614/B

Figure 6. CS4281 PCI Audio Controller

RD4281-15

DS3

08R

D15A1

DGND

AGND

DGND

AGND

+5VA

DGND

AGND

+3.3VD

AGND

SPDIF_TX

C49
0.1uF
X7R

C52
0.1uF
X7R

R17

C45

22pF

NPO

C46
22pF
NPO

24.576 MHz

C106

0.01uF

X7R

R66

C50

1.0uF

C51

1.0uF

C107
1000pF

NPO

C53
1000pF
NPO

C54
1000pF
NPO

R104
No Pop

R105

R106

C138
680pF
NPO

C139
680pF
NPO

R18

CS4297A

2
3

12
13
14
15
16
17
18
19
20
21
22
23
24

27
28
29
30

LINE_OUT_R

MONO_OUT

AVdd2

ALT_LINE_OUT_L

nc7

ALT_LINE_OUT_R

AVss2

nc6

nc5

FLTO

FLTI

FLT3D

BCFG

DVdd1

XTL_IN
XTL_OUT

DVss1

SDATA_OUT

BIT_CLK

DVss2

SDATA_IN
SYNC

DVdd2

RESET#

PC_BEEP
PHONE
AUX_L
AUX_R
VIDEO_L
VIDEO_R
CD_L
CD_GND
CD_R
MIC1
MIC2
LINE_IN_L
LINE_IN_R

AVdd1

AVss1

REFFLT
Vrefout
AFLT1
AFLT2

S/PDIF_OUT

EAPD

ID1#

ID0#

LINE_OUT_L

C48
680pF
NPO

C103
680pF
NPO

C47
680pF
NPO

CD_INR

CD_COM

LINE_INR

LINE_INL

MIC1

CD_INL

AUX_R

AUX_L

ASYNC

ASDOUT

ASDIN

ZV_R

PHONE_IN

ARST#

ZV_L

PCBEEP

ALT_LINE_OUTL

ALT_LINE_OUTR

SPDIF_TX

LINE_OUTR

LINE_OUTL

ABITCLK

MONO_OUT

TIE UNUSED ANALOG
INPUTS TO VREF.

DUAL FOOTPRINT LAYOUT
FOR XTAL.

layout Y1 on top of
Y2 -- populate only
one XTAL

Do not populate C107,
C106 for CS4297.

Do not populate R66.

Figure 7. CS4297A Codec

RD4281-15

308

RD15A

AGND

+5VA

AGND

CGND

AGND

+5VA

AGND

+5VA

AGND

R73

2.7K

R72

47K

R75

47K

R74

6.8K

R69

68K

R71
100K

R70
47K

R68
47K

U10A

MC33078D

U10B

MC33078D

C110
1uF

X7R

C109 0.068 uF

X7R

C114
0.1uF
X7R

C111

220pF

NPO

C112

220pF

NPO

C115

220pF

NPO

C108

10UF

C113

10UF

R79

C119
0.1uF
X7R

R80

4
3
5
2
1

MIC1

place close to
pins 8 and 4

Connect CGND
to the jack

1) Do not populate U10, R68, R69, R70,
R71, R72, R74, R75, C113, C114 and C115.

For Microphone Circuit without Op Amp

2) Populate R79, R80 and C119

3) Populate: 2.2K for R73

2.5K for R68

100 ohm for C109
(fits on the same pad)

0.1uF for C110

Do not populate R79

for Pre Amp Mic

Circuit

Do not populate R80
& C119 for Pre Amp

Mic Circuit

Figure 8. Microphone Input Circuit

RD4281-15

DS3

08R

D15A1

+5V_PCI

+3.3VD

DGND

+5V_PCI

CGND

+5V_PCI

R41

10K

R38

39K

MMBT3904LT1

R42

20K

MMBT2907ALT1

R37

100

R30

2.2K

C77
100pF

COG

R32

2.2K

R33

2.2K

R31

2.2K

R40

39K

FIDUCIAL

TOOLHOLE

FIDUCIAL

C78
100pF

COG

C76
1000pF
NPO

C80
12000pF
X7R

C82
12000pF
X7R

C83
12000pF
X7R

C81
12000pF
X7R

R23

47K

R39

5.6K

R26

4.7K

C73
1000pF
NPO

C72

0.1uF

X7R

R24

4.7K

R25

4.7K

J10
DB15

31@100MHz

C74
1000pF
NPO

C75
1000pF
NPO

C79
0.1uF
X7R

R27

4.7K

JAB2

MIDIOUT

MIDIIN

JBCY

JBB2

JACX
JBCX

JACY

JAB1

JBB1

optional MIDI out buffer -- populate as necessary

populate instead of MIDI
out buffer as necessary

Place Near
Inky

Populate R23 for
CS4280

Figure 9. MIDI and Joystick Control

CRD4281-15

DS308RD15A1

DGND

+5V_PCI

+12VD

DGND

+5V_PCI

DGND

+3.3V_PCI

DGND

-12VD

DGND

+3.3V_PCI

+3.3VD

+3.3V_PCI

C/BE0

C/BE3

C/BE1

AD3

AD8

AD4

AD28

AD19

AD24

AD31

AD[31..0]

AD16

AD0

AD6

AD17

AD22

AD1

AD27

AD26

AD30

AD14

AD29

AD10

AD2

AD18

AD23

AD9

AD21

AD25

AD11

AD20

AD13

AD5

AD15

AD7

AD12

C/BE2

C/BE[3..0]#

Side B

PCI BUS 5V B

1
2
3
4
5
6
7
8
9

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62

-12V
TCK
GND11
TDO
+5V(8)
+5V(9)
INTB#
INTD#
PRSNT1#
RSVD(4)
PRSNT2#
GND(12)
GND(13)
RSVD(5)
GND(14)
CLK
GND(15)
REQ#
+5V(10)
AD[31]
AD[29]
GND(16)
AD[27]
AD[25]
+3.3V(7)
C/BE[3]#
AD[23]
GND(17)
AD[21]
AD[19]
+3.3V(8)
AD[17]
C/BE[2]#
GND(18)
IRDY#
+3.3V(9)
DEVSEL#
GND(19)
LOCK#
PERR#
+3.3V(10)
SERR#
+3.3V(11)
C/BE[1]#
AD[14]
GND(20)
AD[12]
AD[10]
GND(21)
KEY3
KEY4
AD[8]
AD[7]
+3.3V(12)
AD[5]
AD[3]
GND(22)
AD[1]
+5V(11)
ACK64#
+5V(12)
+5V(13)

C85
0.1uF
X7R

C86
0.1uF
X7R

C87
0.1uF
X7R

C98
0.1uF
X7R

C94
0.1uF
X7R

C95
0.1uF
X7R

C96
0.1uF
X7R

C97
0.1uF
X7R

R43

No Pop

R44

No Pop

Side A

PCI BUS 5V A

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62

TRST#

+12V

TMS
TDI

+5V(1)

INTA#
INTC#

+5V(2)

RSVD(1)

+5V(3)

RSVD(2)

GND(1)
GND(2)

RSVD(3)

RST#

+5V(4)

GNT#

GND(3)

PME#

AD[30]

+3.3V(1)

AD[28]
AD[26]
GND(4)
AD[24]

IDSEL

+3.3V(2)

AD[22]
AD[20]
GND(5)
AD[18]
AD[16]

+3.3V(3)

FRAME#
GND(6)

TRDY#

GND(7)

STOP#

+3.3V(4)

SDONE

SBO#

GND(8)

PAR

AD[15]

+3.3V(5)

AD[13]
AD[11]
GND(9)

AD[9]

KEY1
KEY2

C/BE[0]#
+3.3V(6)

AD[6]
AD[4]

GND(10)

AD[2]
AD[0]

+5V(5)
REQ64#
+5V(6)
+5V(7)

C93
0.1uF
X7R

C92

10UF

C84

10UF

PAR

STOP#

TRDY#

FRAME#

INTA#

RST#

GNT#

IDSEL

CLK

REQ#

IRDY#

AD[31..0]

DEVSEL#

C/BE[3..0]#

PERR#

PRSNT2#, PRSNT1# = 00
Power Requirement =
7.5W max

PCI BUS

PCI Bus +3.3V supply.
Place near PCI edge
connector

PCI Bus +5V_PCI
Side B near pin
1

Connect AGND to DGND with a 50 mil trace near the CS4297
Connect CGND to DGND with a 50 mil trace near the finger
edge of the board.

Unused PCI Bus +3.3V supply.
Place near PCI edge
connector

POPULATE 0 OHM

RESISTORS ONLY IF 3.3V

IS AVAILABLE ON PCI

BUS AND 3.3V REGULATOR

IS NOT REQUIRED

Figure 11. PCI Bus

CRD4281-15

DS308RD15A1

+3.3VD

DGND

+5V_PCI

DGND

+12VD

+12VA

+5VA

AGND

-12VD

-12VA

AGND

MIC2920A,400ma,SOT223

OUT

GND

MIC2920A,400ma,TO220

OUT

GND

C90

0.1uF

X7R

C91

0.1uF

X7R

MC78L05AC

GND

OUT

C33

0.1uF

X7R

31@100MHz

C30

0.1uF

X7R

31@100MHz

C88

10UF

C89

10UF

C32

10UF

MC78M05ACDT

OUT

GND

C29

10uF ELEC

C31

10uF ELEC

Connect AGND to DGND with a 50 mil trace near the CS4297A

Connect CGND to DGND with a 50 mil trace near the finger

edge of the board.

SURFACE MOUNT

POPULATION

OPTION

PIN IN HOLE

POPULATION

OPTION

U8 OR U9 IS NOT REQUIRED IF

3.3V IS AVAILABLE ON THE

PCI BUS. IF REMOVED, STUFF

0 OHM RESISTORS AS SHOWN ON

PAGE 8. CONTINUE TO

POPULATE C88 - C91.

SURFACE MOUNT

POPULATION

OPTION

PIN IN HOLE

POPULATION

OPTION

5 VA Power

1) CS4297A = 35 mA

2) CS4334 = 15mA

Figure 12

. Po

e
r

CRD4281-15

DS308RD15A1

BILL O

MATER

IALS

Ite

Descri

ption

Reference

Packa

Man

f
.

Part

Number

,ELE

10UF

,
T

H,CAS

A,20%,

C1,C2,

C3,C7,C8,

,
C12,

C99,C100,

C31

C32,C34,

C36

,
C40,C84,

88,

C89,C92,

C10

13,

C131,C135,

136,

C137

H 5

ONI

E-A

16Z

, 0805, C

,
220pF

,

5%, 50V

C4,C5,

C6,C9,C10,

C13

,
C14,

C26,C27,

C10

C102,C1

,C1

12,C1

15,

133,C134

CSN

_0805

C0805C221

J5GAC

CAP

,
0805, C

,
22pF

,

5%, 50V

C25,C28,

C45

,
C46,C130,C132

CSN

_0805

C0805C220

J5GAC

, 0805, X

7R, .1uF

, 10%, 5

C30,C33,

C41

,
C42,C43,

44,

C49,C52,

C57

,
C58,C59,

60,

C61,C62,

C64

,
C65,C66,

67,

C69,C70,

C72

,
C79,C85,

86,

C87,C90,

C91

,
C93,C94,

95,

C96,C97,

C98

,
C

14,C1

16,

17,C1

18,C1

19,

CSN

_0805

C0805C104

K5RA

CAP

,
1.

0UF

,
S

1206,+80/

-
20%,

25V

,
Y

C50,C51

CSN

_1206

GRM42

6Y5

105Z25BL

CAP

,
0805, C

,
680pF

,

10%, 50V

C47,C48,

C10

C129,C138,C139

CSN

_0805

C0805C681

K5GAC

CAP

,
0805, C

,
1000pF

,

10%, 50V

C53,C54,

C56

,
C73,C74,

75,

C76,

107

CSN

_0805

C0805C102

K5GAC

CAP

,
0805,

COG

,

100pF

, 5%, 50V

C77,C78,

C10

C105

CSN

_0805

C0805C101

J5GAC

CAP

,
0805, X

7R, 12000pF

,

10%, 50V

C80,C81,

C82

,
C83

CSN

_0805

C0805C123

K5RA

, 0805, X

7R, 68000pF

,

10%, 50V

C109

CSN

_0805

C0805C683

K5RA

ERM

,
.

1uF

,
10%,

50V

,
X

C106

CSN

_0805

C0805C103

K5RA

, 1206, X

7R, 1uF

,

10%,

25V

CSN

_1206

NKE

C1206X

7R500-

105K

HDR,

025" PIN,

1" CT

,
150u"

SN/PB

1,J4,J1

,J12

CON_M

LX_70553_4

MOLE

70553-000

/8"

PHO

J3,

J14,

-356

ELE

-3056A

-5P

H-2

t
e

-
102-07-G-S

ONN,

15D SHE

LL,

FEM

LE, R

ANGLE

MOUNT

J10

5-HF

747845-3

/D E

ECTRON-

J-2018-1

I
ND

,
F

1206,

31@

100MH

,
25%

L1,

,
L

I
N

D_F

1206

TDK

F50ACB

32161

1-T

I
ND

,
F

1812,

120@

100MH

,
25%

I
N

D_F

1812

TDK

F30ACB

453215-T

I
O

,
DUA

SOT23

OT23

IONAL

7000L

RAN, S

NPN, S

Q6,Q7,

OT23

IONAL

BT3904L

RAN,

, PNP

,
SOT23

OT23

IONAL

BT3906L

,
220K

,
S

0805,5%,1/

10,ME

L F

I
LM

R5,R6,

R95,R96

RES

_0805

PHILIPS

9C08052A

224J

,

SO, 0805, 56

5%, 1/10W

, M

R8,R10,

R92,R94

RES

_0805

PHILIPS

9C08052A

5602J

,

SO, 0805, 27

5%, 1/10W

, M

R9,R1

R34

,
R93,R97

RES

_0805

PHILIPS

9C08052A

2702J

,

SO, 0805, 47

5%, 1/10W

, M

R23,R35,

R36

,
R68,

R70,R72,

R75

,
R89,R90

RES

_0805

PHILIPS

9C08052A

4702J

,
SO,

0805,

,
5%,

,
ME

L F

I
LM

R17,R18,

R19

,
R20

RES

_0805

PHILIPS

9C08052A

47R0J

,
SO,

0805,

4.7K, 5%,

,
ME

L F

I
LM

R21,R24,

R25

,
R26,R27

RES

_0805

PHILIPS

9C08052A

4701J

,
SO,

0805,

2.2K, 5%,

,
ME

L F

I
LM

R30,R31,

R32

,
R33

R101,R102,R103

RES

_0805

PHILIPS

9C08052A

2201J

,
SO,

0805,

5%,

1/10W

,
ME

L F

I
LM

R37,R64,

R65

RES

_0805

PHILIPS

9C08052A

1000J

,

SO, 0805, 10

5%, 1/10W

, M

R63,R99,

R10

_0805

PHILIPS

9C08052A

1002J

CRD4281-15

DS308RD15A1

RES

,
SO,

0805,

6.8K, 1%,

,
ME

L F

I
LM

R45,R46,

R47

,
R48,R49,

50,

R51,R52,

R53

,
R54, R61,R62,R74

RES

_0805

PHILIPS

9C08052A

6801F

,
SO,

0805,

3.4K, 1%,

,
ME

L F

I
LM

R55,R57

RES

_0805

PHILIPS

9C08052A

3401F

,

SO, 0805, 68

5%, 1/10W

, M

R69

RES

_0805

PHILIPS

9C08052A

6802J

,

SO, 0805, 10

0K, 5%, 1/10W

, M

L FI

R71

RES

_0805

PHILIPS

9C08052A

1003J

,
SO,

0805,

2.7K, 5%,

,
ME

L F

I
LM

R73

RES

_0805

PHILIPS

9C08052A

2701J

,
SO,

0805,

1%,

1/10W

,
ME

L F

I
LM

R85

RES

_0805

PHILIPS

9C08052A

374J

,

SO, 0805, 90

.
9

, 1%, 1

/
10W

, M

L FI

R107

RES

_0805

PHILIPS

9C08052A

90J

,
SO,

0805,

5%,

1/10W

,
ME

L F

I
LM

R91

RES

_0805

PHILIPS

9C08052A

3900J

,
SO,

0805,

0, 5%,

,
ME

L F

I
LM

R105,R106

RES

_0805

PHILIPS

9C08052A

0R00J

ulse T

r
ans

f
o

r
m

,
I

ation,

TH-4

Puls

ngi

ering

65612

Dual head

phone

amp

U1,U12

SO8

otorola

1458

V POS

.
VOL

.
,
500m

otorola

78M05A

CDT

I
C, S

,

AC

'
97 2.0 S

RIAL

CODEC

w/ S

48_7X

MI-

COND.

4297A-K

100 P

I
N

I

Cont

r
o

l
ler

MQFP10

MI-

COND.

4281-CM

I
C,

,
SOIC8,

OM,

16 x 8,

SO8

ICROCHIP

24LC00/SN

.
3

S. V

.
R

., 400m

SOT223

MICRE

IC2920A

3.3BS

I
C, S

,

SOIC8,

33078, DUA

L OP

U10

SO8

OROLA

33078D

,

24.

576M

Hz, CA

-301, Fund

Mode, P

Res

XTL_CA

301

SON

-
301_24.576M-C

Document Outline

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: CRD4281-15

Document Outline

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: CRD4281-15